Folding computer keyboards are known in the art. Generally, such prior art folding keyboards fall into two categories: keyboards that fold in half along a line that divides the spacebar, and keyboards that are folded into three or more sections.
The following patents set forth folding keyboards in the first aforesaid category: U.S. Pat. Nos. 6,174,097; 6,575,647; U.S. Pat. D457,525, U.S. Pat. D420,655; U.S. Pat Nos. 6,877,919; 6,972,699; 6,894,626; 6,839,002; 6,803,904; 6,798,649; 6,793,421; 6,698,957; 6,734,809; 6,594,142; 6,679,639; 6,920,039; 6,547,463; 6,585,440; 5,982,612; 5,943,041; 5,703,578; 5,653,543; 5,574,481; 5,457,453; 5,712,760 and 5,933,320.
Most competent typists type by touch. Touch typing is typing using the sense of touch rather than sight to find the keys. Touch typing usually involves placement of the typist's eight fingers in a horizontal row along the middle of the keyboard (the home row) within reach of the other keys. Most computer keyboards have a raised dot or bar on either the F/J keys or the D/K keys (or the keys in the same position, for non-QWERTY keyboards) so that touch-typists can feel them when their fingertips are over the correct home row.
In order for a folding keyboard to ‘feel’ like a standard keyboard to a touch typist, certain properties are generally desirable. One of these properties is a continuous, unbroken space bar that runs from the C key to the M key (on a US keyboard). This also means that the spacebar needs to be five standard key widths wide, or wider. The foregoing prior art suffers from the disadvantage that the space bar is broken.
The second category of patents referred to above, maintains an unbroken spacebar by splitting the keyboard into three or more sections, and then folding the sections together (or stacking them). Although this second category of keyboards provides a better ‘feel’ to the keyboard, the resulting design may include multiple complicated hinge mechanisms, as well as a thicker and/or longer package when the keyboarded is folded.
The following patents set forth folding keyboards in the second aforesaid category of prior art: U.S. Pat. Nos. 3,940,758; 5,519,569; 5,687,058 and 5,995,025.